Abstract: An engine starter includes a motor having a tubular armature rotation shaft, and a rotation output shaft arranged on one axial end side of the motor coaxially therewith to be axially slidably supported. A clutch mechanism is included for transmitting torque from the armature rotation shaft to a rotation output shaft and an electromagnetic switch which has a shifting member to push the aforementioned rotation output shaft by an electromagnetic force in the axial direction to slidably move it. The switch also brings movable contacts in touch with fixed contacts to supply power to the aforementioned motor. A rear part of the rotation output shaft and the front part of the shifting member are inserted into the armature rotation shaft tube from opposite directions. The shifting member of the electromagnetic switch, the armature rotation shaft and the rotation output shaft are all coaxially arranged to reduce the length of the starter.

Abstract: An engine starter comprising a motor having a tubular armature rotation shaft, a rotation output shaft arranged on one axial end of the motor and on the coaxial line with the armature rotation shaft and axially slidably supported, a clutch mechanism for transmitting the turning force of the armature rotation shaft to the rotation output shaft and an electromagnetic switch which not only has a shifting member, by means of an electromagnetic force, to push the rotation output shaft in the axial direction to slidably move it, but which brings movable contacts in touch with fixed contacts, thereby to supply power to the motor. The rear part of the rotation output shaft and the front part of the shifting member inserted into the armature rotation shaft tube from opposite directions, the shifting member of the electromagnetic switch, armature rotation shaft and the rotation output shaft are coaxial.

Abstract: With respect to an armature for use in an electric motor of an engine starter, or the like, an annular steel-plate ring (11) is fitted on the outer circumference of commutator segments (2) through insulating paper (12) for the purpose of stably maintaining strength in the connection between each of the commutator segments (2) to which armature coils (6) are connected and a resinmolding member (3) fixed to an armature rotary shaft (5).

Abstract: A cylindrical yoke 3 of a d.c. motor of an engine starter having a planet reduction gear mechanism and a bracket 5 fitted on an extension of the yoke without relative rotation therebetween is formed integrally on an inner surface of the extension with internal gear teeth 4 of the planet reduction gear mechanism, which mesh with a solar gear 6 formed integrally on an armature shaft 2 of the motor through planet gears 7 supported by a flange 10 of an output shaft 11 of the starter. The motor is separated from the planet reduction gear mechanism by a flange 3b, 22 arranged therebetween and supporting a bearing 16 which supports the armature shaft.

Abstract: A commutator 4 for a starter motor comprises a plurality of segments 4a electrically connected to armature coils 3, an insert member 4b fitted to an armature shaft 2, and a glass-fiber-reinforced phenol resin 4c molded to integrate the segments with the insert member, wherein mica particles in a range of 5%-10% by weight are uniformly contained in the resin.